Slide Rail Assembly

ABSTRACT

A slide rail assembly includes a first rail, a second rail, a mounting member, a third rail, a fourth rail and an engaging member. The mounting member includes a first part, a second part and a third part. The first part and the second part are connected to the third part and respectively extended along different directions. The third rail is connected to the first part of the mounting member, and the third rail is movable relative to the first rail. The fourth rail is connected to the second part of the mounting member, and the second rail is movable relative to the fourth rail. The engaging member is movably mounted to the mounting member. The engaging member is configured to allow the mounting member to be synchronously moved with the second rail along a predetermined direction.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a slide rail, and more particularly, toa slide rail assembly having two or more than two slide rails.

2. Description of the Prior Art

As shown in FIG. 1, in a rack system 100, a carried object 102, such asa drawer, a chassis of an electronic device or the like, is arrangedwith slide rail assemblies 104 at two sides in order to be mounted ontoa rack. Wherein, the rack usually has a plurality of posts, such as apair of front posts 106 and a pair of rear posts (not shown in thefigure), for mounting the slide rail assemblies 104.

Furthermore, a first width W1 defined between the pair of front posts106 of the rack usually meets a standard specification. On the otherhand, an overall width including widths of the two slide rail assemblies104 at two sides (such as second widths W2) and a width of the carriedobject 102 (such as a third width W3) must be corresponding to the firstwidth W1 of the rack. However, the carried object 102 may have adifferent width due to different market requirements (that is, the widthof the carried object 102 may not be equal to the third width W3). Inother words, the width of the slide rail assembly 104 must be changed,so as to allow the entire width of the slide rail assemblies 104 and thecarried object 102 to match the first width W1. Therefore, once themarket requires a wider carried object 102 (that is, the width of theslide rail assembly 104 must be narrower), it is important to develop aslide rail assembly having a limited width with improved structuralstrength or supporting strength.

SUMMARY OF THE INVENTION

The present invention relates to a slide rail assembly having two ormore than two slide rails mounted to each other through a mountingmember.

According to an embodiment of the present invention, a slide railassembly comprises a first rail, a second rail, a mounting member, athird rail, a fourth rail, an engaging member and an elastic member. Themounting member comprises a first part, a second part and a third part.The first part and the second part are connected to the third part andrespectively extended along different directions. The third rail isconnected to the first part of the mounting member, and the third railis movable relative to the first rail. The fourth rail is connected tothe second part of the mounting member, and the second rail is movablerelative to the fourth rail. The engaging member is movably mounted tothe mounting member. The elastic member is configured to provide anelastic force to the engaging member. Wherein, when the second rail ismoved from a retracted position to a first predetermined position alonga first direction, the engaging member is engaged with the second railin response to the elastic force of the elastic member, so as to allowthe mounting member to be synchronously moved with the second rail alongthe first direction.

Preferably, the fourth rail comprises a first wall, a second wall and aside wall connected between the first wall and the second wall of thefourth rail. The second rail comprises a first wall, a second wall and aside wall connected between the first wall and the second wall of thesecond rail. The engaging member is pivoted to the mounting member. Oneof the first wall and the second wall of the fourth rail, has a notch.The notch is configured to allow an engaging part of the engaging memberto insert therein. One of the first wall and the second wall of thesecond rail has an abutting part. When the second rail is located at thefirst predetermined position, the engaging part of the engaging membercontacts the abutting part, in order to allow the second rail to drivethe mounting member to move along the first direction through theabutting part.

Preferably, the slide rail assembly further comprises a working memberarranged on the first rail. When the second rail is moved from the firstpredetermined position to a second predetermined position along thefirst direction, the engaging member is moved by the working member todisengage the engaging part of the engaging member from the abuttingpart, such that the mounting member is no longer synchronously movedwith the second rail.

Preferably, the first part and the second part are substantiallyperpendicularly connected to the third part.

Preferably, the mounting member has a first side and a second side. Thethird rail is connected to the first part of the mounting member andlocated at the first side of the mounting member. The fourth rail isconnected to the second part of the mounting member and located at thesecond side of the mounting member.

Preferably, the first side is opposite to the second side.

Preferably, the first rail comprises a first wall, a second wall and aside wall connected between the first wall and the second wall of thefirst rail. A first passage is defined by the first wall, the secondwall and the side wall of the first rail. The third rail is movablerelative to the first rail through the first passage.

Preferably, the third rail comprises a first wall, a second wail and aside wall connected between the first wall and the second wall of thethird rail. The side wail of the third rail is connected to the firstpart of the mounting member. The first wall and the second wail of thethird rail are located within the first passage.

Preferably, the slide rail assembly further comprises a first slideassisting device movably mounted between the first rail and the thirdrail. The first slide assisting device comprises a plurality of slideassisting members configured to be supported between the first wall ofthe first rail and the first wall of the third rail, and configured tobe supported between the second wall of the first rail and the secondwall of the third rail.

Preferably, the first wall of the first rail has a first section and asecond section bent relative to the first section. The second wall ofthe first rail has a third section and a fourth section bent relative tothe third section.

Preferably, the side wall of the fourth rail is connected to the secondpart of the mounting member. A second passage is defined by the firstwall, the second wall and the side wall of the fourth rail. The secondrail is movable relative to the fourth rail through the second passage.

Preferably, the first wall and the second wall of the second rail arelocated within the second passage.

Preferably, the slide rail assembly further comprises a second slideassisting device movably mounted between the fourth rail and the secondrail. The second slide assisting device comprises a plurality of slideassisting members configured to be supported between the first wall ofthe second rail and the first wall of the fourth rail, and configured tobe supported between the second wall of the second rail and the secondwall of the fourth rail.

Preferably, one of the first wall and the second wall of the first railhas a positioning part. When the mounting member is moved to a thirdpredetermined position along the first direction, the engaging member isengaged with the positioning part of the first rail in response to theelastic force of the elastic member, in order to prevent the mountingmember from being moved relative to the first rail along the firstdirection or a second direction.

Preferably, the slide rail assembly further comprises a buffer memberarranged on the first rail, and a contact member arranged on the thirdtail. When the mounting member is moved a predetermined distance alongthe first direction, the contact member contacts the buffer member forproviding a buffer effect.

Preferably, a first blocking base is arranged adjacent to a front partof the first rail. The slide rail assembly further comprises a holdingbase. The buffer member is mounted between the first blocking base andthe holding base.

Preferably, a second blocking base is arranged adjacent to a front partof the fourth rail. A blocking member is movably connected to the secondrail. When the second rail is moved relative to the fourth rail alongthe first direction to an open position, the blocking member isconfigured to contact a blocking part of the second blocking base at ablocking position, in order to prevent the second rail from beingfurther moved along the first direction, and an operating member isconfigured to be operated to move the blocking member to be no longer atthe blocking position.

Preferably, when the second rail is moved from the open position to apredetermined retracted position along the second direction, the secondrail is configured to drive the engaging member to move, to disengagethe engaging member from the positioning part of the first rail.

According to another embodiment of the present invention, a slide railassembly comprises a first rail, a second rail, a mounting member, athird rail, a fourth rail and an engaging member. The mounting membercomprises a first part, a second part and a third part. The first partand the second part are substantially perpendicularly connected to thethird part and respectively extended along different directions. Thethird rail is connected to the first part of the mounting member, andthe third rail is movable relative to the first rail. The fourth rail isconnected to the second part of the mounting member, and the second railis movable relative to the fourth rail. The engaging member is arrangedon the mounting member. The engaging member is configured to engage withthe second rail, so as to allow the mounting member to be synchronouslymoved with the second rail along a first direction.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a rack system of the prior art.

FIG. 2 is a diagram showing a slide rail assembly according to anembodiment of the present invention;

FIG. 3 is an exploded view of the slide rail assembly according to anembodiment of the present invention;

FIG. 4 is an enlarged view of an area A of FIG. 3;

FIG. 5 is a cross-sectional view of the slide rail assembly according toan embodiment of the present invention;

FIG. 6 is a diagram showing the slide rail assembly in a retracted stateaccording to an embodiment of the present invention;

FIG. 7 is an enlarged view of an area A of FIG. 6;

FIG. 8 is an enlarged view of an area B of FIG. 6;

FIG. 9 is a diagram showing a second rail of the slide rail assemblybeing synchronously moved with a mounting member through an engagingmember when the second rail is moved to a first predetermined positionalong a first direction according to an embodiment of the presentinvention;

FIG. 10 is an enlarged view of an area A of FIG. 9;

FIG. 11 is a diagram showing a working member on a first rail contactingthe engaging member during a process of the second rail and the mountingmember of the slide rail assembly being moved to a second predeterminedposition along the first direction according to an embodiment of thepresent invention;

FIG. 12 is a diagram showing the mounting member being unsynchronizedwith the second rail by the working member when the second rail and themounting member of the slide rail assembly are moved to the secondpredetermined position along the first direction according to anembodiment of the present invention;

FIG. 13 is a diagram showing the working member contacting the engagingmember during a process of the mounting member of the slide railassembly being moved to a third predetermined position along the firstdirection according to an embodiment of the present invention;

FIG. 14 is a diagram showing the engaging member being engaged with apositioning part of the first rail when the mounting member of the sliderail assembly is moved to the third predetermined position along thefirst direction according to an embodiment of the present invention;

FIG. 15 is a diagram showing the mounting member contacting a buffermember through a contact member when the second rail is moved to aposition along the first direction according to an embodiment of thepresent invention;

FIG. 16 is an enlarged view of an area A of FIG. 15;

FIG. 17 is a diagram showing the mounting member further contacting thebuffer member through the contact member when the second rail is movedto an open position along the first direction according to an embodimentof the present invention;

FIG. 18 is an enlarged view of an area A of FIG. 17;

FIG. 19 is a diagram showing the second rail being located at the openposition according to an embodiment of the present invention;

FIG. 20 is a diagram showing the second rail contacting the engagingmember during a process of the second rail of the slide rail assemblybeing moved from the open position along a second direction according toan embodiment of the present invention;

FIG. 21 is a diagram showing the engaging member being driven by thesecond rail to be disengaged from the positioning part of first railduring a process of the second rail of the slide rail assembly beingfurther moved along the second direction according to an embodiment ofthe present invention; and

FIG. 22 is a diagram showing a rack system of the present invention.

DETAILED DESCRIPTION

As shown in FIG. 2, a slide rail assembly 20 of the present inventioncomprises a first rail 22, a second rail 24, a third rail 26, a fourthrail 28 and a mounting member 30.

As shown in FIG. 3 to FIG. 5, the first rail 22 and the second rail 24are up-down arranged and parallel to each other, such that the firstrail 22 and the second rail 24 are arranged at different heights. In thepresent embodiment (please refer to FIG. 5), the first rail 22 isarranged above the second rail 24. However, in an alternativeembodiment, the second rail 24 can be arranged above the first rail 22.The present invention is not limited thereto. The third rail 26 and thefourth rail 28 are respectively fixedly connected to a first part 44 aand a second part 44 b of the mounting member 30. Wherein, the thirdrail 26 is movable relative to the first rail 22, and the second rail 24is movable relative to the fourth rail 28.

The first rail 22 comprises a first wall 32 a, a second wall 32 b and aside wall 34 connected between the first wall 32 a and the second wall32 b of the first rail 22. A first passage 36 is defined by the firstwall 32 a, the second wall 32 b and the side wall 34. The first rail 22has a front part 22 a and a rear part 22 b.

The mounting member 30 is arranged in an N-like shape. The first part 44a and the second part 44 b of the mounting member 30 are arranged as anupper part and a lower part respectively. Preferably, the mountingmember 30 further comprises a third part 44 c. In the presentembodiment, the third part 44 c is substantially a horizontal part, butthe present invention is not limited thereto. The first part 44 a andthe second part 44 b are substantially perpendicularly connected to twoportions of the third part 44 c and respectively extended alongdifferent directions. For example, the first part 44 a is extendedupward, and the second part 44 b is extended downward.

The third rail 26 is connected to the first part 44 a of the mountingmember 30 and located at a first side L1 of the mounting member 30. Thethird rail 26 is movable relative to the first rail 22 through the firstpassage 36. Wherein, the third rail 26 comprises a first wall 46 a, asecond wall 46 b and a side wall 48 connected between the first wall 46a and the second wall 46 b of the third rail 26. The side wall 49 of thethird rail 26 is connected to the first part 44 a of the mounting member30. The first wall 46 a and the second wall 46 b of the third rail 26are located within the first passage 36. Preferably, the slide railassembly 20 further comprises a first slide assisting device 50 movablymounted between the first rail 22 and the third rail 26. The first slideassisting device SO comprises a plurality of slide assisting members,such as a first slide assisting member 50 a and a second slide assistingmember 50 b. The first slide assisting member 50 a and the second slideassisting member 50 b can be balls, rollers or the like. The first slideassisting member 50 a is configured to be supported between the firstwall 32 a of the first rail 22 and the first wall 46 a of the third rail26. The second slide assisting member 50 b is configured to be supportedbetween the second wall 32 b of the first rail 22 and the second wall 46 b of the third rail 26. Preferably, the first wail 32 a of the firstrail 22 has a first section SI and a second section S2 bent relative tothe first section SI, and the second wall 32 b of the first rail 22 hasa third section S3 and a fourth section S4 bent relative to the thirdsection S3. According to such arrangement, structural strength orsupporting strength of the first rail 22 can be improved.

The fourth rail 28 is connected to the second part 44 b of the mountingmember 30 and located at a second side L2 of the mounting member 30. Thesecond side L2 is opposite to the first side L1. The fourth rail 28comprises a first wall 52 a, a second wall 52 b and a side wall 54connected between the first wall 52 a and the second wall 52 b of thefourth rail 26. The side wall 54 of the fourth rail 29 is connected tothe second part 44 b of the mounting member 30. A second passage 56 isdefined by the first wall 52 a, the second wall 52 b and the side wall54 of the fourth rail 28. The second rail 24 is movable relative to thefourth rail 28 through the second passage 56.

The second rail 24 comprises a first wall 58 a, a second wall 58 b and aside wall 60 connected between the first wall 58 a and the second wall58 b of the second rail 24. The first wall 58 a and the second wall 58 bof the second rail 24 are located within the second passage 56.Preferably, the slide rail assembly 20 further comprises a second slideassisting device 62 movably mounted between the fourth rail 28 and thesecond rail 24. The second slide assisting device 62 comprises aplurality of slide assisting members, such as a first slide assistingmember 62 a and a second slide assisting member 62 b. The first slideassisting member 62 a and the second slide assisting member 62 b can beballs, rollers or the like. The first slide assisting member 62 a isconfigured to be supported between the first wail 58 a of the secondrail 24 and the first wall 52 a of the fourth rail 28, and the secondslide assisting member 62 b is configured to be supported between thesecond wall 58 b of the second rail 24 and the second wall 52 b of thefourth rail 26.

Preferably, as shown in FIG. 3, FIG. 6 and FIG. 7, the slide railassembly 20 further comprises an engaging member 54 and an elasticmember 66. The engaging member 64 is movably mounted to the mountingmember 30. In the present embodiment, the engaging member 64 is pivotedrelative to the mounting member 30 through a shaft member 67. Theelastic member 66 has an elastic part 65 (please also refer to FIG. 4)for providing an elastic force to the engaging member 64. Furthermore,one of the first wall 52 a and the second wail 52 b of the fourth rail28 has a hole or a notch 68. The notch 68 is configured to allow a firstengaging part 70 of the engaging member 64 to insert therein.Preferably, the engaging member 64 further has a second engaging part71. Wherein, the shaft member 67 is located between the first engagingpart 70 and the second engaging part 71. Preferably, the elastic part 65of the elastic member 66 abuts against a portion of the engaging member64 adjacent to the second engaging part 71. Preferably, one of the firstwall 58 a and the second wall 58 b of the second rail 24 has an abuttingpart 72. In the present embodiment, the second rail 24 has a space H(such as a hole, a groove, or a notch) for accommodating the firstengaging part 70 of the engaging member 64, and the abutting part 72 isa wall around the space H.

Preferably, as shown in FIG. 3 and FIG. 6, the slide rail assembly 20further comprises a working member 74 arranged on the first rail 22. Inthe present embodiment, the working member 74 is connected to the secondwall 32 b of the first rail 22. The working member 74 is configured towork with the engaging member 64.

Preferably, as shown in FIG. 3 and FIG. 6, one of the first wall 32 aand the second wall 32 b of the first rail 22 has a positioning part 76.The positioning part 76 can be a groove, a hole or a notch.

Preferably, as shown in FIG. 3 and FIG. 6, the slide rail assembly 20further comprises a buffer member 38 arranged on the first rail 22. Inthe present embodiment, the buffer member 38 is arranged adjacent to thefront part 22 a of the first rail 22 (please also refer to FIG. B), andthe buffer member 38 can be a soft pad or made of a soft, plasticmaterial, but the present invention is not limited thereto. Preferably,a first blocking base 40 and a holding base 42 are arranged adjacent tothe front part 22 a of the first rail 22. The buffer member 38 ismounted between the first blocking base 40 and the holding base 42.Wherein, the buffer member 38 is located at a position corresponding toa blocking wall 41 of the first blocking base 40. The blocking wall 41is configured to abut against the buffer member 38.

Preferably, as shown in FIG. 3 and FIG. 6, the slide rail assembly 20further comprises at least one contact member 78 arranged on the thirdrail 26. The contact member 78 is configured to work with the buffermember 38. The contact member 78 can be an independent componentconnected to the third rail 26; or, the contact member 78 can beintegrally formed on the third rail 26. In the present embodiment, thecontact member 78 is a protrusion protruded from the side wall 48 of thethird rail 26, but the present invention is not limited thereto.

Preferably, as shown in FIG. 3 and FIG. 6, a second blocking base 80 isarranged adjacent to a front part 28 a of the fourth rail 28, and ablocking member 82 is movably connected (such as pivoted) to the sidewall 60 of the second rail 24. Preferably, an elastic base 83 isconfigured to provide an elastic force to the blocking member 82, and anoperating member 84 is configured to be operated to deflect the blockingmember 82. first wall 32 a and the second wall 32 b of the first rail 22has a positioning part 76. The positioning part 76 can be a groove, ahole or a notch.

Preferably, as shown in FIG. 3 and FIG. 6, the slide rail assembly 20further comprises a buffer member 38 arranged on the first rail 22. Inthe present embodiment, the buffer member 38 is arranged adjacent to thefront part 22 a of the first rail 22 (please also refer to FIG. B), andthe buffer member 38 can be a soft pad or made of a soft, plasticmaterial, but the present invention is not limited thereto. Preferably,a first blocking base 40 and a holding base 42 are arranged adjacent tothe front part 22 a of the first rail 22. The buffer member 38 ismounted between the first blocking base 40 and the holding base 42.Wherein, the buffer member 38 is located at a position corresponding toa blocking wall 41 of the first blocking base 40. The blocking wall 41is configured to abut against the buffer member 38.

Preferably, as shown in FIG. 3 and FIG. 6, the slide rail assembly 20further comprises at least one contact member 78 arranged on the thirdrail 26. The contact member 78 is configured to work with the buffermember 38. The contact member 78 can be an independent componentconnected to the third rail 26; or, the contact member 78 can beintegrally formed on the third rail 26. In the present embodiment, thecontact member 78 is a protrusion protruded from the side wall 48 of thethird rail 26, but the present invention is not limited thereto.

Preferably, as shown in FIG. 3 and FIG. 6, a second blocking base 80 isarranged adjacent to a front part 28 a of the fourth rail 28, and ablocking member 82 is movably connected (such as pivoted) to the sidewall 60 of the second rail 24. Preferably, an elastic base 83 isconfigured to provide an elastic force to the blocking member 82, and anoperating member 84 is configured to be operated to deflect the blockingmember 82.

As shown in FIG. 13 and FIG. 14, when the mounting member 30, the thirdrail 26 and the fourth rail 28 are moved relative to the first rail 22along the first direction Dl to a predetermined position, such as athird predetermined position P3, the engaging member 64 is deflected bythe elastic force released from the elastic member 66 (or the elasticpart 65 of the elastic member 661 to be engaged with the positioningpart 76 of the first rail 22 through the second engaging part 71.Meanwhile, the first engaging part 70 of the engaging member 64 islocated in the notch 68 of the fourth rail 28, in order to prevent themounting member 30 from being moved relative to the first rail 22 alongthe first direction D1 or a second direction D2 opposite to the firstdirection D1. Preferably, the working member 74 has a guiding section75, such as an inclined surface or an arc surface. Through contactingthe guiding section 75, the engaging member 64 can be guided to move thesecond engaging part 71 to be engaged with the positioning part 76 ofthe first rail 22. Meanwhile, the mounting member 30, the third rail 26and the fourth rail 28 are in an open state or an extended staterelative to the first rail 22.

As shown in FIG. 15 to FIG. 19, when the mounting member 30 is in theopen state, the second rail 24 can be moved relative to the fourth rail28 along the first direction D1 to an open position P4, and the blockingmember 82 can contact a blocking part 81 of the second blocking base 80at a blocking position X1, in order to prevent the second rail 24 frombeing further moved along the first direction D1. Wherein, if the secondrail 24 is pulled out to move at high speed along the first directionD1, an impact force between the blocking member 82 and the blocking part81 of the second blocking base 80 is strong accordingly. Therefore, thecontact member 73 is configured to contact the buffer member 38 toprovide a buffer effect and reduce impact noise. In the presentembodiment, the contact member 78 is configured to contact a first endpart 38 a of the buffer member 38 through the holding base 42, and asecond end part 38 b of the buffer member 38 is configured to abutagainst the blocking wail 41 of the first blocking base 40 (as shown inFIG. 18) for providing a buffer effect, such that the mounting member 30or related components of the slide rail can be protected. Preferably,the holding base 42 is movably mounted to the first rail 22. Forexample, the holding base 42 has two supporting legs 42 a respectivelyextending into elongated grooves 27 (or elongated holes) of the firstrail 22. Therefore, the holding base 42 can be slightly driven by thecontact member 78 to push the buffer member 38, such that the buffermember 38 can abut against the blocking wall 41 of the first blockingbase 40 to provide the buffer effect. However, in an alternativeembodiment, the contact member 78 can directly push the buffer member38. Such arrangement can also provide the buffer effect and protectrelated components of the slide rail.

As shown in FIG. 19, when the mounting member 30, the third rail 26 andthe fourth rail 28 are in the open state, the second rail 24 can bemoved relative to the fourth rail 28 along the first direction Dl to theopen position P4. In addition, when a user applies a force F to theoperating member 84, a disengaging part 84 a of the operating member 84further moves the blocking member 82 to be no longer located at theblocking position X1 (for example, the blocking member 82 is located atan unblocking position X2), such that the blocking member 82 no longercontacts the blocking part 81 of the second blocking base 80 to allowthe second rail 24 to be further moved along the first direction D1 anddetached from the fourth rail 28. Or, when the second rail 24 is locatedat the open position P4, the user can retract the second rail 24 fromthe open position P4 along the second direction D2.

As shown in FIG. 20 and FIG. 21, when the second rail 24 is moved fromthe open position P4 to a predetermined retracted position P5 along thesecond direction D2, the second rail 24 is configured to drive theengaging member 64 to deflect. As such. the elastic member 66 (or theelastic part 65 of the elastic member 66) accumulates an elastic force,and the second engaging part 71 of the engaging member 64 is no longerengaged with the positioning part 76 of the first rail 22. In otherwords, the mounting member 30 is movable relative to the first rail 22along the second direction D2, such that the second rail 24, themounting member 30, the third rail 26 and the fourth rail 28 can beretracted relative to the first rail 22 along the second direction D2.

As shown in FIG. 22, two sides of a carried object 88 can be mounted toa first post 90 a and a second post 90 b of a rack through a pair ofslide rail assemblies 20. A first width Yl is defined between the firstpost 90 a and the second post 90 b. Wherein, the first width Y1 of therack is substantially equal to the first width W1 of the rack of theprior art (please also refer to FIG. 11. In addition, FIG. 22 only showsthe first rail 22, the second rail 24, the mounting member 30, the thirdrail 26 and the fourth rail 28 of the slide rail assembly 20 forsimplification.

Furthermore, the carried object 88 of the present invention has a thirdwidth Y3 wider than the third width W3 of the carried object 102 of theprior art (as shown in FIG. 1). As such, a width of the slide railassembly 20 (a second width Y2) of the present invention must be smallerthan the second width W2 of the slide rail assembly 104 of the priorart. However, since the third rail 26 and the fourth rail 28 of thepresent invention are respectively connected to two different parts ofthe mounting member 30 in order to work with the first rail 22 and thesecond rail 24, structural strength or supporting strength of the sliderail assembly 20 can be improved accordingly even though the width ofthe slide rail assembly 20 is limited.

Therefore, the slide rail assembly of the present invention ischaracterized in that:

1. The third rail 26 is movable relative to the first rail 22, and thesecond rail 24 is movable relative to the fourth rail 28; wherein thefirst rail 22 and the second rail 24 are up-down arranged and parallelto each other, such that the first rail 22 and the second rail 24 arearranged at different heights. Such arrangement is different from theslide rail assembly of the prior art having two or more than two sliderails arranged at a same height. The third rail 26 and the fourth rail28 of the present invention are connected to two different parts (suchas the upper part and the lower part) of the mounting member 30, inorder to work with the first rail 22 and the second rail 24 to meet,width limitation. As such, the slide rail assembly 20 can comprise morethan two slide rails and have a smaller width.

2. The third rail 26 and the fourth rail 28 are connected to twodifferent parts of the mounting member 30 in order to work with thefirst rail 22 and the second rail 24. As such, the structural strengthor supporting strength of the slide rail assembly 20 can be improved.

3. When the second rail 24 is moved to a predetermined position alongthe first direction D1, the mounting member 30, the third rail 26 andthe fourth rail 28 can be synchronously moved with the second rail 24through the engaging member 64.

4. When the second rail 24 is moved to an open position (such as acompletely open position), the contact member 78 is configured tocontact the buffer member 38 in order to prevent the blocking member 82at the blocking position X1 from directly contacting or colliding withthe blocking part 81 of the second blocking base 80.

5. In addition to allowing the mounting member 30 to be synchronouslymoved with the second rail 24, the engaging member 64 is also configuredto engage with the first rail 22, in order to prevent the mountingmember 30 from being moved relative to the first rail 22 along the firstdirection D1 or the second direction D2.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A slide rail assembly, comprising: a first rail;a second rail; a mounting member comprising a first part, a second partand a third part, wherein the first part and the second part areconnected to the third part and respectively extended along differentdirections; a third rail connected to the first part of the mountingmember, wherein the third rail is movable relative to the first, rail; afourth rail connected to the second part of the mounting member, whereinthe second rail is movable relative to the fourth rail; an engagingmember movably mounted to the mounting member; and an elastic memberconfigured to provide an elastic force to the engaging member; whereinwhen the second rail is moved from a retracted position to a firstpredetermined position along a first direction, the engaging member isengaged with the second rail in response to the elastic force of theelastic member, so as to allow the mounting member to be synchronouslymoved with the second rail along the first direction.
 2. The slide railassembly of claim 1, wherein the fourth rail comprises a first wall, asecond wail and a side wall connected between the first wall and thesecond wall of the fourth rail, the second rail comprises a first wall,a second wall and a side wall connected between the first wall and thesecond wall of the second rail, the engaging member is pivoted to themounting member, one of the first wall and the second wall of the fourthrail has a notch, the notch is configured to allow an engaging part ofthe engaging member to insert therein, and one of the first wall and thesecond wall of the second rail has an abutting part; when the secondrail is located at the first predetermined position, the engaging partof the engaging member contacts the abutting part, in order to allow thesecond rail to drive the mounting member to move along the firstdirection through the abutting part.
 3. The slide rail assembly of claim2, further comprising a working member arranged on the first rail,wherein when the second rail is moved from the first predeterminedposition to a second predetermined position along the first direction,the engaging member is moved by the working member to disengage theengaging part of the engaging member from the abutting part, such thatthe mounting member is no longer synchronously moved with the secondrail.
 4. The slide rail assembly of claim 3, wherein the first part andthe second part ore substantially perpendicularly connected to the thirdpart.
 5. The slide rail assembly of claim 4, wherein the mounting memberhas a first side and a second side, the third rail is connected to thefirst part of the mounting member and located at the first side of themounting member, and the fourth rail is connected to the second part ofthe mounting member and located at the second side of the mountingmember.
 6. The slide rail assembly of claim 5, wherein the first side isopposite to the second side.
 7. The slide rail assembly of claim 5,wherein the first rail comprises a first wall, a second wall and a sidewail connected between the first wall and the second wall of the firstrail, a first passage is defined by the first wall, the second wall andthe side wall of the first rail, and the third rail is movable relativeto the first rail through the first passage.
 8. The slide rail assemblyof claim 7, wherein the third rail comprises a first wall, a second walland a side wail connected between the first wall and the second wall ofthe third rail, the side wall of the third rail is connected to thefirst part of the mounting member, and the first wall and the secondwall of the third rail are located within the first passage.
 9. Theslide rail assembly of claim 8, further comprising a first slideassisting device movably mounted between the first rail and the thirdrail, wherein the first slide assisting device comprises a plurality ofslide assisting members configured to be supported between the firstwall of the first rail and the first wall of the third rail, andconfigured to be supported between the second wall of the first rail andthe second wail of the third rail.
 10. The slide rail assembly of claim7, wherein the first wall of the first rail has a first section and asecond section bent relative to the first section, and the second wallof the first rail has a third section and a fourth section bent relativeto the third section.
 11. The slide rail assembly of claim 9, whereinthe side wall of the fourth rail is connected to the second part of themounting member, a second passage is defined by the first wall, thesecond wall and the side wall of the fourth rail, and the second rail ismovable relative to the fourth rail through the second passage.
 12. Theslide rail assembly of claim 11, wherein the first wall and the secondwall of the second rail are located within the second passage.
 13. Theslide rail assembly of claim 12, further comprising a second slideassisting device movably mounted between the fourth rail and the secondrail, wherein the second slide assisting device comprises a plurality ofslide assisting members configured to be supported between the firstwall of the second rail and the first wall of the fourth rail, andconfigured to be supported between the second wall of the second railand the second wall of the fourth rail.
 14. The slide rail assembly ofclaim 13, wherein one of the first wall and the second wall of the firstrail has a positioning part; when the mounting member is moved to athird predetermined position along the first direction, the engagingmember is engaged with the positioning part of the first rail inresponse to the elastic force of the elastic member, in order to preventthe mounting member from being moved relative to the first rail alongthe first direction or a second direction.
 15. The slide rail assemblyof claim 13, further comprising a buffer member arranged on the firstrail, and a contact member arranged on the third rail, wherein when themounting member is moved a predetermined distance along the firstdirection, the contact member contacts the buffer member for providing abuffer effect.
 16. The slide rail assembly of claim 15, wherein a firstblocking base is arranged adjacent to a front part of the first rail,the slide rail assembly further comprises a holding base, and the buffermember is mounted between the first blocking base and the holding base.17. The slide rail assembly of claim 14, wherein a second blocking baseis arranged adjacent to a front part of the fourth rail, and a blockingmember is movably connected to the second rail; when the second rail ismoved relative to the fourth rail along the first direction to an openposition, the blocking member is configured to contact a blocking partof the second blocking base at a blocking position, in order to preventthe second rail from being further moved along the first direction, andan operating member is configured to be operated to move the blockingmember to be no longer at the blocking position.
 18. The slide railassembly of claim 17, wherein when the second rail is moved from theopen position to a predetermined retracted position along the seconddirection, the second rail is configured to drive the engaging member tomove, to disengage the engaging member from the positioning part of thefirst rail.
 19. A slide rail assembly, comprising: a first rail; asecond rail; a mounting member comprising a first part, a second partand a third part, wherein the first part and the second part aresubstantially perpendicularly connected to the third part andrespectively extended along different directions; a third rail connectedto the first part of the mounting member, wherein the third rail ismovable relative to the first rail; a fourth rail connected to thesecond part of the mounting member, wherein the second rail is movablerelative to the fourth rail; and an engaging member arranged on themounting member, wherein the engaging member is configured to engagewith the second rail, so as to allow the mounting member to besynchronously moved with the second rail along a first direction. 20.The slide rail assembly of claim 19, wherein the fourth rail comprises afirst wall, a second wall and a side wall connected between the firstwall and the second wall of the fourth rail, the second rail comprises afirst wall, a second wall and a side wall connected between the firstwall and the second wall of the second rail, the engaging member ispivoted to the mounting member, one of the first wall and the secondwall of the fourth rail has a notch, the notch is configured to allow anengaging part of the engaging member to insert therein, and one of thefirst wall and the second wall of the second rail has an abutting part;when the second rail is located at the first predetermined position, theengaging part of the engaging member contacts the abutting part, inorder to allow the second rail to drive the mounting member to movealong the first direction through the abutting part; wherein the sliderail assembly further comprises a working member arranged on the firstrail; when the second rail is moved to a second predetermined positionalong the first direction, the engaging member is moved by the workingmember to disengage the engaging part of the engaging member from theabutting part, such that the mounting member is no longer synchronouslymoved with the second rail.